Sandbox vectors

Let’s define some vectors which can be used for demonstrations:

manyNumbers <- sample( 1:1000, 20 )
manyNumbers
 [1] 894  60 723 751 762 799 605 973 721 705 978 985 625   5 685 297 867  63 109 682
manyNumbersWithNA <- sample( c( NA, NA, NA, manyNumbers ) )
manyNumbersWithNA
 [1] 867  60  63   5 723 762 682  NA 109  NA 685 978 721 894 625 973 705 605 799  NA 985 751 297
duplicatedNumbers <- sample( 1:5, 10, replace = TRUE )
duplicatedNumbers
 [1] 3 5 4 1 5 5 1 1 2 5
letters
 [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z"
LETTERS
 [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"
mixedLetters <- c( sample( letters, 5 ), sample( LETTERS, 5 ) )
mixedLetters
 [1] "n" "g" "o" "s" "d" "U" "C" "V" "H" "G"

Are all/any elements TRUE

all( manyNumbers <= 1000 )
[1] TRUE
all( manyNumbers <= 500 )
[1] FALSE
any( manyNumbers > 1000 )
[1] FALSE
any( manyNumbers > 500 )
[1] TRUE
all( !is.na( manyNumbers ) )
[1] TRUE
any( is.na( manyNumbers ) )
[1] FALSE

Which elements are TRUE

Input: logical vector Output: vector of numbers (positions)

which( manyNumbers > 900 )
[1]  8 11 12
which( manyNumbersWithNA > 900 )
[1] 12 16 21
which( is.na( manyNumbersWithNA ) )
[1]  8 10 20

Filtering vector elements

manyNumbers[ manyNumbers > 900 ] # indexing by logical vector
[1] 973 978 985
manyNumbers[ which( manyNumbers > 900 ) ] # indexing by positions
[1] 973 978 985
somePositions <- which( manyNumbers > 900 )
manyNumbers[ somePositions ]
[1] 973 978 985

Are some elements among other elements

"A" %in% LETTERS
[1] TRUE
c( "X", "Y", "Z" ) %in% LETTERS
[1] TRUE TRUE TRUE
all( c( "X", "Y", "Z" ) %in% LETTERS )
[1] TRUE
all( mixedLetters %in% LETTERS )
[1] FALSE
any( mixedLetters %in% LETTERS )
[1] TRUE
mixedLetters[ mixedLetters %in% LETTERS ]
[1] "U" "C" "V" "H" "G"
mixedLetters[ !( mixedLetters %in% LETTERS ) ]
[1] "n" "g" "o" "s" "d"
manyNumbers %in% 300:600
 [1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
which( manyNumbers %in% 300:600 )
integer(0)
sum( manyNumbers %in% 300:600 )
[1] 0

Pick one of two (three) depending on condition

if_else( manyNumbersWithNA >= 500, "large", "small" )
 [1] "large" "small" "small" "small" "large" "large" "large" NA      "small" NA      "large" "large" "large" "large" "large" "large" "large" "large" "large" NA      "large" "large"
[23] "small"
if_else( manyNumbersWithNA >= 500, "large", "small", "UNKNOWN" )
 [1] "large"   "small"   "small"   "small"   "large"   "large"   "large"   "UNKNOWN" "small"   "UNKNOWN" "large"   "large"   "large"   "large"   "large"   "large"   "large"   "large"  
[19] "large"   "UNKNOWN" "large"   "large"   "small"  
# here integer 0L is needed instead of real 0.0 
# manyNumbersWithNA contains integer numbers and the method complains
if_else( manyNumbersWithNA >= 500, manyNumbersWithNA, 0L ) 
 [1] 867   0   0   0 723 762 682  NA   0  NA 685 978 721 894 625 973 705 605 799  NA 985 751   0

Duplicates and unique elements

unique( duplicatedNumbers )
[1] 3 5 4 1 2
unique( c( NA, duplicatedNumbers, NA ) )
[1] NA  3  5  4  1  2
duplicated( duplicatedNumbers )
 [1] FALSE FALSE FALSE FALSE  TRUE  TRUE  TRUE  TRUE FALSE  TRUE

Positions of max/min elements

which.max( manyNumbersWithNA )
[1] 21
manyNumbersWithNA[ which.max( manyNumbersWithNA ) ]
[1] 985
which.min( manyNumbersWithNA )
[1] 4
manyNumbersWithNA[ which.min( manyNumbersWithNA ) ]
[1] 5
range( manyNumbersWithNA, na.rm = TRUE )
[1]   5 985

Sorting/ordering of vectors

manyNumbersWithNA
 [1] 867  60  63   5 723 762 682  NA 109  NA 685 978 721 894 625 973 705 605 799  NA 985 751 297
sort( manyNumbersWithNA )
 [1]   5  60  63 109 297 605 625 682 685 705 721 723 751 762 799 867 894 973 978 985
sort( manyNumbersWithNA, na.last = TRUE )
 [1]   5  60  63 109 297 605 625 682 685 705 721 723 751 762 799 867 894 973 978 985  NA  NA  NA
sort( manyNumbersWithNA, na.last = TRUE, decreasing = TRUE )
 [1] 985 978 973 894 867 799 762 751 723 721 705 685 682 625 605 297 109  63  60   5  NA  NA  NA
manyNumbersWithNA[1:5]
[1] 867  60  63   5 723
order( manyNumbersWithNA[1:5] )
[1] 4 2 3 5 1
rank( manyNumbersWithNA[1:5] )
[1] 5 2 3 1 4
sort( mixedLetters )
 [1] "C" "d" "g" "G" "H" "n" "o" "s" "U" "V"

Ranking of vectors

manyDuplicates <- sample( 10:15, 10, replace = TRUE )
rank( manyDuplicates )
 [1]  4.0  8.5 10.0  8.5  6.0  4.0  7.0  4.0  1.5  1.5
rank( manyDuplicates, ties.method = "min" )
 [1]  3  8 10  8  6  3  7  3  1  1
rank( manyDuplicates, ties.method = "random" )
 [1]  4  8 10  9  6  5  7  3  1  2

Rounding numbers

v <- c( -1, -0.5, 0, 0.5, 1, rnorm( 10 ) )
v
 [1] -1.00000000 -0.50000000  0.00000000  0.50000000  1.00000000 -0.47120119 -1.38365350 -0.14892750  0.12315171  0.44401498 -0.02007903 -0.61077459 -0.02546202 -0.87237029 -0.47276226
round( v, 0 )
 [1] -1  0  0  0  1  0 -1  0  0  0  0 -1  0 -1  0
round( v, 1 )
 [1] -1.0 -0.5  0.0  0.5  1.0 -0.5 -1.4 -0.1  0.1  0.4  0.0 -0.6  0.0 -0.9 -0.5
round( v, 2 )
 [1] -1.00 -0.50  0.00  0.50  1.00 -0.47 -1.38 -0.15  0.12  0.44 -0.02 -0.61 -0.03 -0.87 -0.47
floor( v )
 [1] -1 -1  0  0  1 -1 -2 -1  0  0 -1 -1 -1 -1 -1
ceiling( v )
 [1] -1  0  0  1  1  0 -1  0  1  1  0  0  0  0  0

Naming vector elements

heights <- c( Amy = 166, Eve = 170, Bob = 177 )
heights
Amy Eve Bob 
166 170 177 
names( heights )
[1] "Amy" "Eve" "Bob"
names( heights ) <- c( "AMY", "EVE", "BOB" )
heights
AMY EVE BOB 
166 170 177 
heights[[ "EVE" ]]
[1] 170

Generating grids

expand_grid( x = c( 1:3, NA ), y = c( "a", "b" ) )
# A tibble: 8 × 2
      x y    
  <int> <chr>
1     1 a    
2     1 b    
3     2 a    
4     2 b    
5     3 a    
6     3 b    
7    NA a    
8    NA b    

Generating combinations

combn( c( "a", "b", "c", "d", "e" ), m = 2, simplify = TRUE )
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "a"  "a"  "a"  "a"  "b"  "b"  "b"  "c"  "c"  "d"  
[2,] "b"  "c"  "d"  "e"  "c"  "d"  "e"  "d"  "e"  "e"  
combn( c( "a", "b", "c", "d", "e" ), m = 3, simplify = TRUE )
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "a"  "a"  "a"  "a"  "a"  "a"  "b"  "b"  "b"  "c"  
[2,] "b"  "b"  "b"  "c"  "c"  "d"  "c"  "c"  "d"  "d"  
[3,] "c"  "d"  "e"  "d"  "e"  "e"  "d"  "e"  "e"  "e"  


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